Nowadays cooked and ready meals for human and pet consumption are really common. A conspicuous part of such food is sold in flexible flat/pillow or stand-up pouches. Pouches are produced and filled in line or as a two-step production. During the filling process several ingredients are inserted in solid and liquid states while the pouch is kept open. After filling, the pouch is sealed on the top and may pass through a thermal process for pasteurisation or sterilisation. However, part of the ingredients during filling can touch the inner walls of the pouch, and if this material does not flow down inside the pouch quickly, it will contaminate the sealing area and the pouch will not be sealed completely compromising food integrity.
A possible technological solution is to use ultrasonic sealing tool that is normally an expensive investment and not suitable for all material structures. With the same principle, when the consumer will empty the pouch, part of the meal will get in contact with pouch walls, and food which is not fast flowing out of the pouch will be quite inconvenient for the consumer that would need to use tools or shake/squeeze the pouch with the risk to spread food around. In case of pet food, consumers are even less keen in using a tool or touch the food by trying to empty the pouch. This explains why having a pouch exhibiting easy and fast flowing of the food along the inner walls can strongly reduce rejections during filling, decrease food safety risk and be an important consumer convenience feature in the field of ready meals and wet pet food in pouches. As an example, ready meal pouches may contain meat, vegetables, rice in gravy or sauce added during filling and juice produced by the food during retort cooking. Pet food pouches may contain meat based food in jelly or gravy and juice produced during retort. Ready sauce pouches may be vegetable, meat or fat (eggs, butter) based and sterilised or pasteurised.
EP-A-1 808 291 discloses a packaging material made of thermoplastic polymers suitable for packaging foods. To prevent pasty and fatty foods from adhering to packaging material, a nonstick composition comprising a fatty ester of a polyhydric alcohol having at least one fatty acid radical per ester molecule with 19 or more carbon atoms is incorporated into at least one selected area of a polymer packaging material. A permanent nonstick effect is observed even if the fatty acid ester is included only in surface-close regions or layers of the packaging material. The outer layer in which the fatty acid ester additive is contained can be a sealing layer. The packaging preferably has the form of a pouch.
WO 2004/050357 A1 discloses a laminate useful in the manufacture of packages for containers, in particular ovenable resistant food containers. The laminate includes a substrate, preferably of a paperboard, and a food contact release layer comprising a blend of polymethylpentene and polypropylene bonded to one side of the substrate. The food contact release layer has a lower surface tension than the food product to come into contact with the release layer and thus offers a good release from food products, particularly those containing high levels of starch and sugar.
WO 2005/092609 A1 discloses a coextruded biaxially oriented PET film with food release properties having a sealable skin layer comprising a hot melt adhesive resin. The skin layer may further comprise fatty aides, waxes or silicon oils and particulate substances such as silica, clay and calcium carbonate.
WO 2008/009865 A1 discloses a fluoropolymer having antibacterial activity. Onto the fluoropolymer there is grafted at least one unsaturated monomer comprising a functional group functional group providing the antibacterial activity and an anion. The functional group providing antibacterial activity is a quaternary ammonium group, a phosphonium group, or a saturated or unsaturated heterocycle comprising a nitrogen atom, chosen from piperidine, piperazine, morpholine, thiomorpholine, thiazole, isothiazole, pyrazole, indole, indazole, imidazole, benzimidazole, quinoline, isoquinoline, benzotriazole, benzothiazole, benzoisothiazole, benzoxazole, benzoxazine, isoxazole, pyrrole, pyrazine, pyrimidine, pyridazine, quinazoline and acridine.
EP 1 174 457 A1 discloses a biaxially oriented polyester film with release properties in aqueous environment. The film, which is used in metal cans as inner release coating, comprises a polyester in which ethylene terephthalate units and/or ethylene naphthalate units are the main structural components, and a wax compound and for silicon compound.
U.S. Pat. No. 6,528,134 B1 discloses a coextruded film with release and dead fold properties for packaging cheese. The film comprises three layers of polyethylene or polypropylene and glycerol monostearate as cheese release agent.
From the aforementioned prior art documents, packaging films having antistick or release properties are known.
EP 2 208 604 A1 discloses a packaging pouch made of a flexible mono or multilayer film for packaging viscous jelly and/or gravy matrix food, in which a thermo cycle such as retort, pasteurisation, hot filling or aseptic conditions are applicable. The surface of a layer of the film forming the pouch inner walls or a surface coating on the film being in contact with food comprises a substance based on a molecule and or molecules system, defined as mixture of different molecular weight and/or molecular structure, functionalised by siloxane and/or fluorinated groups so that the surface tension of the layer or the surface coating on the layer is 24 mN/m or less and the pouch inner walls being in contact with food exhibit easy flow properties.